The prior art is replete with numerous disclosures directed to percutaneous access/subcutaneous devices. As disclosed therein, such devices are useful when frequent or long-term access to the body is required, as in kidney dialysis, drug delivery, intravenous feeding, ostomies, and transmission of energy to intracorporeal or blood pumps. Typically, such access port devices are surgically implanted under the skin and generally include an outlet opening connected by means of a tubular conduit (catheter) system to a blood vessel within the body.
For example, in U.S. Pat. No. 5,527,278, there is described an access port for implantation within the body of a patient for providing repeated access to a specific site within the patient and communicating with the site by an implanted internal catheter. The access port includes a housing having an inlet orifice leading to a reduced diameter guide passageway. An external filament such as a needle, guidewire, optical fiber external catheter can be introduced into the access device, and fed through the housing. This system is said to allow for the introduction of therapeutic agents, the removal of fluids from the body, or the introduction of sensing and articulating devices to the specific site within the patient.
In U.S. Pat. No. 5,399,168, there is described a subcutaneous implantable access port formed of a housing having a pair of non-circular fluid cavities enclosed therein by a floor, walls upstanding from the floor, and a self-sealing septum system above each fluid cavity. The access ports thereby provide a plurality of needle-penetrable, self-sealing septums, each affording repeated access to a corresponding plurality of distinct fluid cavities each in communication with a plural lumen catheter.
In U.S. Pat. No. 5,167,638, there is reported a multi-chamber subcutaneously implantable infusion port and catheter assembly formed from a small number of plastic components that are easily injection molded and assembled. The components are constructed so that a catheter assembly is easily and securely bonded to the port. In addition, the '638 patent makes reference to the fact that the access port has an anchoring base made of flexible biocompatible materials such as silicon rubber.
In U.S. Pat. No. 4,897,081 there is disclosed a percutaneous access device (PAD) for long term skin penetration and use as an access port in the body of a patient. The PAD is said to include a flat flange or skirt, formed from a semiflexible material such as a semirigid polyurethane. The skirt contains on its surface two "stages" or regions of biocompatible material. The first stage is described to be of biocompatible polytetrafluoroethylene (PTFE) having pore sizes of about 50-125 microns and a thickness of about 0.020 inches. Optional to PTFE, it is suggested that one can employ a polyurethane, such as "Tecoflex" filaments, which are said to have excellent cell attachment characteristics. The second stage is described as a dacron polyester woven fabric with loose strands to allow for cell infiltration. The '081 patent goes on to emphasize that there is a downgrowth of epidermal cells through the first stage and the formation of mature collagen in the second stage.
Attention is also directed to U.S. Pat. No. 5,318,545, which describes a composite implantable biocompatible vascular access port for delivering a fluid medication, and U.S. Pat. No. 5,405,325, which discloses an areterial access port which is grafted directly into the vascular system. In addition, European Patent Application No. 90908334 describes an implantable vascular access device which includes a port said to be made of a biocompatible housing, and a septum which is also said to include a biocompatible, self-resealing, penetrable material.
However, as can be seen upon review of the above prior art, a significant drawback of the presently available skin penetration devices relates to the difficulty of attaching said devices by standard suturing procedures. Typically, in the skirt which surrounds the access devices of the prior art, small openings are provided to allow for anchoring of the PAD or subcutaneous device to the patient. This is best illustrated in U.S. Pat. No. 4,673,393, which emphasizes that the PAD housing contains in the skirt or flange section thereof evenly spaced apertures which provides an opening that must be aligned with the suture needle for suturing the device to a layer of tissue when implanting. Accordingly, in the suturing of such devices, the physician has to make absolutely certain that suturing proceeds through these limited openings in order to guarantee that the PAD/subcutaneous device will be immobilized in the desired location. That being the case, current PAD/subcutaneous designs do not readily permit an easy and convenient method for implanting the PAD or subcutaneous device at a desired location within the body.
Accordingly, it is an object of this invention to provide an improved percutaneous/subcutaneous access device, for vascular access, utilizing in lieu of standard sutures, an implantable, integral fabric, mesh material or perforated film of polymer or other biocompatible material. The material may be readily sutured or stapled into place at any position thereof without the need for surgical needle alignment, as noted above, and the implantable fabric can be integral to the device or placed over the device to retain it in the body.
It is also an object of this invention to provide a design configuration while having specific utility for the placement of a PAD or subcutaneous device, further provides a convenient method for immobilizing other types of medical devices in the body, such as a pacemaker.